1. Field of the Invention
The present invention relates to a keytop component that allows easy changing of printed indications along with a function change, an operation key having the keytop component, and an electronic device, such as a copy machine and a fax machine, having the operation key.
2. Description of the Related Art
Conventionally, operations panels of electronic devices, such as copy machines and fax machines, have been provided with various operation keys.
FIG. 12 schematically illustrates the configuration of a related-art operation key.
The operation key shown in FIG. 12 comprises a keytop component 51 and a key switch 61. The keytop component 51 serves as an operation button. An indication representing its function is printed on the upper surface of the keytop component 51. The key switch 61 is located under the keytop component 51 and configured to be turned on when the keytop component 51 is pressed.
To prevent the keytop component 51 from being separated from a cover 53 during use, the keytop component 51 includes locking claws 52 that are inserted into holes formed in the cover 53 so as to lock the keytop component 51 to the cover 53. Patent Documents 1 and 2 disclose related-art keytop components.
[Patent Document 1] Japanese Utility Model Registration No. 3083182
[Patent Document 2] Japanese Patent Laid-Open Publication No. 10-269001
When the function of the operation key is changed, the keytop component is replaced by another keytop component on which characters, symbols and the like representing a new function are printed.
For replacing the keytop component 51 by another keytop component, the keytop component 51 is removed by disassembling the operations panel or by applying force against the locking claws 52. This may result in losing components or damaging the keytop component 51 and the cover 53.
These problems may be avoided by, for example, reducing the insertion depth of the locking claws 52 of the keytop component 51 so as to facilitate the removal of the keytop component 51. However, reducing the insertion depth of the locking claws 52 makes the keytop component 51 more likely to come off during use.
For example, the operation key comprising the keytop component 51 is required to securely complete an input even when an end section of the keytop component 51 is pressed. In the case where the keytop component 51 has a rectangular top surface, if an end section of the top surface in its longitudinal direction is pressed, the locking claw 52 formed at the opposite end section, which serves as a support point upon turning on the key switch 61, might come off because of its reduced insertion depth, and thus failing to turn on the key switch 61.
An example of a keytop replacing method is disclosed in Patent Document 1. With the disclosed method, however, a keytop might not be securely fixed to a component (keytop sheet) to which the keytop is attached, or the keytop might come off because of a small insertion depth of a claw.